Echinococcosis/hydatidosis: its prevalence,economic and public health significance in Tigray region,North Ethiopia

A cross sectional study was carried out to assess the prevalence, economic and public health significance of echinococcosis/hydatidosis in Tigray Regional State, north Ethiopia. Out of 18 stray dogs euthanized and examined, three of them were found harboring the adult parasite Echinococcus granulosus in their small intestine. From 5,194 cattle examined at slaughter houses, 1146 (22.1%) of them were found harboring hydatid cyst. The majority of the infected cattle had hydatid cyst in both liver and lungs. The hydatid cyst infection in the lung, liver, kidney, heart and spleen were found to be 13%, 8.1%, 0.5%, 0.4%, and 0.1%, respectively. The estimated total annual loss from bovine hydatidosis due to offal condemnation (lungs and liver) and carcass weight loss was 25,608 Ethiopian (Eth.) Birr. The present human hydatidosis survey conducted in all six zonal hospitals of Tigray Regional State disclosed one active clinical case in Mekelle hospital during the study period. While, the retrospective data analyses of the six zonal hospitals indicated that eight cases of human hydatidosis were diagnosed since 2000. Thus echinococcosis/hydatidosis is considerably prevalent disease in cattle and it is a serious public health concern in Tigray region.     

Evaluation of the efficacy of anthelmintics sold on Ethiopian markets against <Emphasis Type="Italic">Haemonchus contortus</Emphasis> in experimentally infected Sheep

A total of 54 lambs, aged between 6–8 months were experimentally infected with Haemonchus contortus to evaluate the efficacy of different anthelmintic brands sold on Ethiopian markets using the faecal egg count reduction test (FECRT) and controlled anthelmintic efficacy trial. Accordingly four different albendazole (Alzole®, Analgon-300®, Albenjung_s® and Ahshialben-300®), two tetramisole (Tetsole® and Ashitetra 600) and two tetramisole-oxyclozanide (Tetraclozan sheep® and Tetraclozash 900®) brands were evaluated at the dosage rates recommended by the manufacturers. Animals were allocated into nine groups of six animals each, and balanced for faecal egg counts (FEC), based on their pre-treatment FEC and treatments were randomized among the groups. One group was kept untreated as a control. Faecal egg count was conducted on day 30 post-infection (day of treatment) and on the 10th day post-treatment. Evaluation of anthelmintics based on FECRT revealed high efficacy (99.55–100% reduction in FEC) for all anthelmintic brands tested against H. contortus. The worm count reduction test using controlled anthelmintic efficacy trial also supported the above finding with 99–100% efficacy of the tested anthelmintics. Therefore, the suspicion on the anthelmintic products as being substandard in quality is not credible, at least, for the brands investigated in this study and it might rather be attributed to under dosing. The need for a good extension system for livestock producers with regard to good anthelmintic usage practices, in light of the inevitable development of anthelminitic resistance, is emphasized. Regular surveillance and laboratory quality evaluation of the anthelmintic products in Ethiopia is indicated.     

Survey of tick infestation in small ruminants of Miesso district,West Harergie,Oromia Region,Ethiopia

A survey was conducted to identify tick species and determine the prevalence of tick infestation in small ruminants of Miesso District, West Harergie Zone. Collection and identification of the ticks were undertaken from November 2007 to April 2008. All visible individual adult ticks were collected from the body of 328 goats and 40 sheep. The prevalence of tick infestation in goats and sheep was found to be 89.9% and 87.5%, respectively. In this study, ten species of ticks which grouped under four genera were identified. The most abundant species found in this study were Boophilus decoloratus (60%), Rhipicephalus pulchellus (25.1%), and Amblyomma gemma (11%). Hyalomma dromedarii was the minor species observed on goats. The difference in the prevalence of tick infestation between sheep and goats was not statistically significant (Χ ²   = 0.22, p = 0.63) but found to be statistically significant between male and females (Χ ²  = 9.8, p = 0.003). Attention should be given to the control and prevention of ticks, since they cause sever damage to the skins of small ruminants and thereby reduce the foreign exchange of the country; they also transmit some diseases which can cause sever loss to the productivity of these animals.     

Current status of bovine cysticercosis of slaughtered cattle in Addis Ababa Abattoir,Ethiopia

The prevalence of Taenia saginata cysticercosis in cattle slaughtered for meat in Addis Ababa Abattoir, Ethiopia between September 2004 and August 2005 was reported. The examination of various organs of 11227 cattle in Addis Ababa Abattoir showed that 842 (7.5%) were infected with T. saginata cysticercosis. The tongue, masseter muscles, cardiac muscles, triceps muscles and thigh muscles were the main predilection sites of the cysts. The cysts of bovine cysticercosis were also identified on the spleen, intercostal muscles, diaphragm and liver. Out of 10329 male cattle, examined, 783 (7.6%) had cysts of bovine cysticercosis while 59 (6.6%) of the 898 female animals investigated were infected. The animals slaughtered were all adults. No significant difference in prevalence rates was recorded between the sexes. The prevalence of bovine cysticercosis was higher in local zebu cattle breeds than Holstein-Frisian cattle.     

Associations of biophysical factors with faba bean root rot (Fusarium solani) epidemics in the northeastern highlands of Ethiopia

Two field surveys were conducted during the 2010 and 2011 cropping seasons to determine the distribution and importance of faba bean root rot, Fusarium solani (Mart) Apple and Sacc. in the northeastern highlands of Ethiopia. The associations of the root rot incidence and severity with independent variables was analyzed using a logistic regression model. The associations of disease incidence and severity with biophysical factors were evaluated. The disease incidence and severity varied among soil types, crop management practices and cropping seasons. Disease incidence and percentage severity index were higher in 2010 (44.6%) than 2011 (44.4%) due to the high rainfall in 2010. Cropping season, soil type, land preparation and weed management practices were significantly associated with faba bean root rot incidence and percentage severity index in a multiple-variable model. A root rot incidence of ≤50% and severity of ≤40% showed high probability of association with season, furrow sowing and weed management practice, whereas vertisols, flat sowing, high soil moisture and high weed density had significant contributions to root rot epidemics. In contrast, elevation, cropping system and crop density were not associated with the root rot incidence and percentage severity index. Our results showed that root rot is a major biotic constraint in the study area and suggested that proper soil drainage and weed management practices could contribute to reduce the impact of the disease until resistant faba bean genotypes are developed and distributed to small-scale faba bean growers in northeastern Ethiopia and other similar areas of the country.     

Causes of lamb morbidity and mortality in the Ethiopian highlands

A study was conducted to investigate causes of lamb morbidity and mortality on farms and on-station at Debre Berhan during 1989 and 1990. It showed pneumonia (bacterial and/or verminous), starvation-mismothering exposure (SME) complex, gastrointestinal parasites, enteritis, abomasal impaction and physical injuries to be important health constraints on productivity. Neonatal mortalities were 51.5% and 46.3% on farms and on-station respectively and occurred owing to management problems such as SME, abomasal impaction and physical injuries. On the farms the lamb birth weight was 2.56±0.25 kg and was significantly (p<0.05) affected by the dam's age, lambing weight, litter size, sex of lamb and year of lambing, but not by the season of lambing. Birth weight significantly (p<0.05) influenced lamb mortality. Lambs with a low birth weight tended to die from SME. Morbidities and mortalities due to infectious causes increased in older lambs, suggesting that infections were acquired with age when resistance was lowered owing to inadequate nutrition and poor management.Heavy loss of lambs could be overcome by such health management interventions as foster mothering, warming lambs during the cold season and vaccination with polyvalent vaccines against pasteurellosis, clostridial infection andDictyocaulus filaria.     

Farmers' highland maize (Zea mays L.) selection criteria: Implication for maize breeding for the Hararghe highlands of eastern Ethiopia

Despite the presence of large numbers of improved maize cultivars, farmers in the Hararghe highlands of eastern Ethiopia persistently grow local cultivars and are not benefiting from the varietal improvement program. By growing local cultivars farmers obtain an average yield of 1.2 t ^-1 whereas research has released cultivars yielding 5–11 t ^-1under on-station conditions. Recognizing this and the important role maize is playing in the livelihood system of farmers in eastern Ethiopia; Participatory Varietal Selection (PVS) was conducted for three consecutive seasons (1996–1998) in three locations. The objectives of the study were to identify farmers' cultivar selection criteria for future breeding, to enable farmers to assess the performance of improved cultivars under their management, to increase farmers' access to the cultivars of their preference by injecting source seed into the local seed system, and to investigate whether breeding for wide adaptation like for the Hararghe highlands has any drawbacks or not. The study indicated farmers' maize varietal selection criteria together with the differences in selection criteria across locations classified under the same adaptation zone. Though farmers selected some of the many improved cultivars tested, no improved cultivar had all the characteristics, which farmers want in a single cultivar. To be able to combine cultivar selection traits farmers considered cultivar combinations in all locations, but not the single `best' cultivar. Despite the yield advantage of hybrids, farmers selected Open Pollinated Varieties (OPVs) because they had more preferred traits. Farmers also preferred to retain their local cultivars despite their lower yield compared to most of the improved cultivars. Both situations confirmed how resource poor farmers' cultivar requirements are much more diverse than yield per se. Gender and social group-driven difference in cultivar preference was also observed. The study revealed the need for proper zoning of the Hararghe highlands as a prerequisite to developing better adapted maize cultivars to the varied agro ecological and socioeconomic niches. As shown in this study, proper zoning, due consideration to farmers' relevant selection traits and wider use of participatory approaches should be adapted to develop cultivars which can gain farmers acceptance. This revised version was published online in August 2006 with corrections to the Cover Date.     

Soil respiration characteristics of tropical soils from agricultural and forestry land-uses at Wondo Genet (Ethiopia) in response to C, N and P amendments

In most parts of tropical Africa, conversion of forests into agricultural lands is often accompanied by drastic changes in soil properties. However, little study has been done to examine changes in biological properties of soils from different land-uses in response to addition of C and nutrients. We conducted this study with the aim of investigating nutrient limitations for microbial activity in soils from agricultural (farm) and forest land-uses at Wondo Genet (Ethiopia) after amendment with C and limiting nutrients. We measured CO₂ respiration rates from the soils incubated in the laboratory before and after addition of glucose-C together with N and/or P in excess and/or limiting amounts. Based on the respiration kinetics, we determined the basal respiration (BR), substrate-induced respiration (SIR), specific-microbial growth rate (μ), respiration maxima (R_max), % of glucose-C respired, and microbially available N and P in the soils. We found that N was more limiting than P for the micro-biota in the soils considered, suggesting the presence of ample amounts of indigenous P that could be extracted by the micro-biota, if provided with C. Addition of P resulted in a respiration pattern with two peaks, presumably reflecting different N pools being available over time. The SIR, Respiration maxima, μ and microbially available P were higher in soils from the farm, while %C respired was higher in the forest, suggesting increased C costs for micro-biota to be able to utilize nutrients that are strongly bound to organic-matter or clay minerals. Depending on land-use, about 49-69% of added glucose-C was respired during two and a half weeks time, but differences between N or P additions were not significant. The correlation between soil physical and chemical properties and respiration parameters, however, depended on whether N or P was limiting. We concluded that examining the soil respiration kinetics could provide vital information on nutritional status of micro-organisms under different land-uses and on potential availability of nutrients to plants.     

Changes of<Emphasis Type="Italic"> Sorghum bicolor</Emphasis> landrace diversity and farmers’ selection criteria over space and time,Ethiopia

Temporal and spatial changes of sorghum landrace diversity and related factors in five farming communities in north Shewa and south Welo, between 1992/1993 and 2000/2001, were studied in order to ascertain the stability of a range of factors that support the maintenance of the crop genetic diversity. The same farmers were interviewed and the same sorghum fields were surveyed both times. Over the 8-year period: the total area planted to sorghum decreased drastically in all five farming communities and a large percentage of the farmers in the communities (Hayk, 69%; Borkena, 68%; Epheson, 51%; Merewa Adere, 72%; and Bati, 54%) decreased the field size planted to sorghum, because of population growth, land redistribution policy, seasonal changes, and stagger cropping followed by interspecies crop displacement; landrace richness increased significantly in Merewa and Borkena, but decreased significantly in Bati, Epheson and Hayk; and farmers’ selection criteria, the reasons for growing specific landraces, increased significantly (10 in 1992/1993 vs. 22 in 2000/2001). Significant differences in field size distribution occur among the five farming communities. In 2000/2001, 22 “generalist” landraces (grown widely across three or more communities), and 46 “specialist” landraces (niche specific, restricted to certain microhabitats in one or two communities) were found. Landrace gains and losses from the farms surveyed in individual communities over the period are demonstrated.     

Geographical, altitude and agro-ecological differentiation of isozyme and hordein genotypes of landrace barleys from Ethiopia: implications to germplasm conservation

An analysis of the variability of genes encoding six isozyme systems (15 loci) and two storage proteins (2 loci) in landrace barley from Ethiopia is reported. The materials consisted of populations collected from sites as low as 1650 and as high as 3750 meters, covering a wide range of agro-ecological conditions and geographical areas. Of the 17 loci 7 were polymorphic and 10 monomorphic when the 95% criterion of polymorphism was applied. Despite the disproportionate monomorphic loci, polymorphism was detected in all populations when this criterion is used. The populations were found to possess fairly low mean number of alleles per locus (A = 1.5), low mean value of expected heterozygosity (H = 0.134) and a fairly high mean percentage of polymorphic loci (P = 35.3%). The mean F_ST= 0.474 for the populations is typical of inbreeding species. The result indicated that allelic richness is concentrated in altitude class 3 (2500–3000 m) followed by altitude class 1 (<2000 m). Altitude class 2 (2000–2500) holds an intermediate place though it is the highest in terms of expected heterozygosity (H = 0.245). Higher genetic diversity is concentrated in some geographical regions such as Shewa, Arsi, Bale compared to others (Welo, Gamu Gofa, Gojam). Genetic differentiation among the agro-ecological zones was more profound than both among the altitudes and among regions. Correlation analysis between phenotypic diversity (Shannon-Weaver diversity index) and expected heterozygosity (H) for isozyme/hordein loci revealed non significant associations except with respect to agro-ecological zones. In general, it was detected that sites in highland areas in central and northern regions may be more desirable for in situ conservation than sites in peripheral regions in terms of isozyme/hordein diversity and current rate of varietal replacement.